Pong Ultimate

I'm working on a Pong clone written with Cocoa and OpenGL, hosted at github: http://github.com/mk12/Pong-Ultimate . Its mainly for myself to learn, but I actually want to make it a fun game with lots of features, like different game modes, as far as pong can stretch anyway. I'm focusing a lot on code correctness and good design, and making it a very polished application from the user's perspective. The OpenGL code is completely legacy free/forward compatible. I'm thinking I'll be able to reuse a lot of the code (and things I learn from it) in other 2d games. Anyone is welcome to help, on code or other things like art and sound.